PHILADELPHIA (AP)  The handcuffed arrest of two black men at a Philadelphia Starbucks served as a fresh reminder of the perils of “retail racism” that African-Americans and minorities encounter on a regular basis.

It happens when minority customers are treated differently than white customers through a variety of indignities and slights. That includes being refused service or reported to security or police over something mundane.

In a 2016 Gallup poll, 52 percent of black respondents said they perceived discrimination in stores downtown or in the shopping mall.

Starbucks announced Tuesday that it would close its 8,000 U.S. stores for several hours next month to conduct racial-bias training for its nearly 175,000 workers.